Magnetic separators for ducts



Feb. 12, 1957 D. E. STEM MAGNETIC SEPARATORS FOR DUCTS 5 SheetsSheet 1Filed Sept. 13, 1954 INVENTOR. Dan 4w 5. 5 2 4 Feb. 12, 1957 D. E. STEMMAGNETIC SEPARATORS FOR DUCTS 3 Sheets-Sheet 2 Filed Sept. 13, 1954INVENTOR. fiat 40.0 E 57 1 4 Feb. 12, 1957 D. E. STEM MAGNETICSEPARATORS FOR DUCTS 3 Sheets-Sheet 3 Filed Sept. 13, 1954 INVENTOR.flan 441) E, 575

MAGNETIC SEIARATORS FOR DUCTS Donald E. Stem, Santa Rosa, Calif.

Application September 13, 1954, Serial No. 455,421 8 Claims. (Cl.209-423 This invention relates to magnetic separators and particularlyto ducts with magnetic separators.

This application is a continuation in part of my pending U. S.application, Serial No. 53,926, now Patent No. 2,699,871, filed October11, 1948, for Magnetic Separator.

The primary object of this invention is to provide in connection withducts for handling loose material like hay, and the like atcomparatively higher rate of speed, a device to efficiently trapmagnetic particles from the material traveling through the duct; thefeatures of the present magnetic duct and particularly the magnet whichrender it more efiicient and prevent re-entry of magnetic particles intothe material blown through the duct, include the following features: theopposite magnetic plates are each made in two magnetic sectionsseparated by a non-magnetic strip and are highly polished and eachmagnet forms a north and south pole on the magnetic plate with the samepolarity of the adjacent plates being nearer together so as to repelparticles around and into the groove formed behind the free edge of eachplate; the magnetic plate fits closely to the opposite sides of the ductand so that the plates are movable along the sides when swung open andclosed but leave a minimum open slit or margin; a casting is formed forthe complete inclosure of the magnet on the door thereby to prevent anymagnetic particles to adhere to the magnet directly; the provision ofcompletely enclosed magnet on the door of the duct; and in gravityoperation the selective control of the flow of material to permitcleaning of a magnet without interrupting the duct operation.

I am aware that some changes may be made in the general arrangements andcombinations of the several devices and parts, as well as in the detailsof the construction thereof without departing from the scope of thepresent invention as set forth in the following specification, and asdefined in the following claims; hence, I do not limit my invention tothe exact arrangements and combinations of the said device and parts asdescribed in the said specification, nor do I confine myself to theexact details of the construction of the said parts as illustrated inthe accompanying drawings.

With the foregoing and other objects in view, which will be mademanifest in the following detailed description, reference is had to theaccompanying drawings for the illustrative embodiment of the invention,wherein:

Fig. 1 is a perspective view of my duct with the door closed.

Fig. 2 is a perspective view of my duct with both doors open.

Fig. 3 is a side view of the duct with the casing being broken away toshow the position of the doors.

Fig. 4 is a perspective view of the enclosed door structure.

Fig. 5 is a cross-sectional view of the closed door structure with themagnet therein.

Fig. 6 is a fragmental edge view of the inside of the door.

2,781,128 Patented Feb. 12-, 1957 Fig. 7 is a front view of the ductwith a modified baflle arrangement.

Fig. 8 is a side View of said modified arrangement; and

Fig. 9 is a sectional, fragmental view of a bafiie in the duct.

In the illustrative embodiment I provide a duct 1 which has an inlet 2at the bottom and an outlet 3 at its top in axial alignment. The inlet 2and outlet 3 have suitable flanges thereon so as to form restrictedpassages at each end of the duct.

On opposite walls 6 and 7 of the duct are provided door structures 8spaced from one another longitudinally with respect to the duct 1. Eachdoor structure 8 is hinged at its lower edge by hinge structure 9 sothat the door can swing outwardly or toward the inlet 2.

One of the novel features of the structure is the arrangement of thedoor 8. Each door structure 8 includes a door plate 11 and a handle 12on the outside face of it for easier handling, and a latch device 13 onthe side of the duct 1 adjacent to the upper edge 14 of the door plate11 for latching the door in closed position.

The opening 16 on the respective sides of the duct is somewhat smallerthan the outside contour of the door plate 11 so as to be completelycovered thereby.

From the inner face of each door plate 11 extends in wardly at rightangles a wall 17 to form the top of a compartment. Vertical side walls18 of generally triangular shape form the sides of the compartmentwithin "ice which a permanent magnet 19 is concealed in the mannershownin Fig. 5. A pocket '21 is formed in the door plate 11 for the purposeof accommodating one portion of the horseshoe exterior of the permanentmagnet 19.

The open side formed between the inner edges of the walls 17 and 18 iscovered by a magnetic plate 22. Each magnetic plate 22 fits very closelythe width of the duct so as to reduce side clearance to a minimum.

This magnetic plate 22 is made of two magnetic strips 23 and 24connected by a non-magnetic strip or gap 26 so as to form an integralplate of a smooth surface which on account of the connection to theopposite poles of the magnet 19 have opposite polarity. in the hereinarrangement, the section 24 of the magnetic plate 22 nearer to the topof the lower door is of a north polarity while the other section 23 issout polarity. The section 23 nearer to the hinge of the upper door isalso of north polarity, while the outer or free end section 24 of theupper door is south polarity. The free edge of the upper segment 24 ofeach magnetic plate projects beyond the top wall 17 of the adjacent doorand is rounded at its edge. A pocket or groove 27 is thus formed betweenthe top plate 17 and the extension of the top section 24 of the magneticplate within which the magnetic particles separated from the materialare collected.

This arrangement is such that the free edge of the lower section ofnorth polarity is closer to the north polarity portion of the uppermagnetic plate, with the result that magnetic particles polarized on theupper.

section of the lower magnetic plate will be repelled by the lowerportion of the upper magnetic plate so as to be returned into the pocket27 and behind the free edge of the lower plate. 7

In the modified form shown in Figs. 7, 8 and 9 there is provided aso-called gravity type of duct where the material flows by gravitythrough the duct. form there can be provided an arrangement for sodirecting the flow of material as to permit the cleaning of the magnetwithout interrupting the operation of the duct. a

In such:

In this form the duct 31 has an intake 32 at its top and the outlet 33at the bottom. Between the inlet and outlet are the magnetic traps orplates generally denoted by the numerals 34 and 35 which instructure arethesame as the magnetic traps heretoforej described in connection withthe first form. These magnets in this instance are-inclined downwardlyandinwardly oflthe trap named rtoward the outlet 33 thereof, The.polarity of the magnetic plates isarranged the same way espreviously sothat the portions of the magnetic platesnearer to one another have thesame'polarity so that the particles get into the magnetic field of'thesubsequent mag net and they, are repelled by that field so as to-turnaround 'the edge of the first magnetic plate and be trapped behind thesame. In general it is to heuriderstood that the-magnetic particleswhich first hit: the portion of the magnet polarized south for instance,are themselves polarized south so that they are attracted toward thenorth side when they move over the same where ultimately they arerepolarized again to north polarity so thatinstead of passing toward orinto the magnetic field of the next magnet which is also north, they arerepelled around and are trapped behind the free edge of the first plate.K

For directing the'flow of material through the duct, I provide baffles36. One of thebafiles above the upper magnet 3 2- and the other baffie36 is between the two magnets. While the bailies work in oppositedirections, structurally and operationally they are the same, thereforethe description of one will sufiice. Each baffie consists of a baflleplate 37 which closely fits across the entire Width of the duct arrangedin an initial posi tion at right angles to the plane of the adjacentmagnetic plate of the magnet. This bafile plate 37 is supported on afulcrum or pivot shaft 38 at the lower end thereof. The shaft 38 isjournalled in suitable journals on the respective opposite sides of theduct 31 and has on one end thereof a handle 39 for manipulating from theoutside. The positions of the'bafiles'37' are defined by oppositeabutments 41 and 42. The abutment 41 determines the position where freedropping or flow'of material is allowed against and unto the adjacentmagnet. The abutment 42 determines the cleaning position of the baffle37, where the bafiie 37 substantially covers the cross-sectional areaabove the magnetic plate of the upper magnet 34 and prevents thematerial from dropping on the magnet 34. Thus flow is limited to thehalf of the duct away from the magnet 34 and the magnet 34 may be swungopen and cleared of trapped magnetic particles. These stops 41 and 42are on the outside of the duct and generally adjacent to the respectivehandles 39 so that the handles 39 rest upon the respective stops in therespective positions.

In operation this duct is more efiicient and-superior to previous ductsin view of the novel features in connection with the totally encloseddoor, with the very close vicinity of its edges to the side plate formovement in and out yet obstructing the passage practically completely,and the particular polarization of the magnetic plate. The above incombination with the suspending of the doors at the lower edges for easyswinging out of the duct passage for cleaning results in a superiorseparator for passages wherein the duct is interconnected. The bafflearrangement provides for superior gravity type operation.

I claim: 7 V 1. In a device 'for separating magnetic from nonmagneticmaterials blown under pressure to -a duct, said duct having an openingon aside thereof between an inlet and an outlet of said duct, a doorhinged on said side to cover. said opening and being swingable outwardlyinto open position, a closedframe on the'inside face of the door closedon its side and top so asto form an inclined plate support opening, amagnetic plate covering said opening, a magnet .enclosedin said frameand on said magnetic plate, the width of said magnetic plate being suchthat the side edges of said plate are in immediate proximity of theadjacent sides of the duct to.

obstruct flow past the side edges of said plate, said plate being heldinclined so as to face the flow through said duct.

2. in a device for separating magnetic from nonmagnetic materials blownunder pressure to a duct, said duct having an opening on aside thereofbetween an inlet and an outlet of said duct, a door hinged on said sideto cover" said opening and being swingable outwardly into open position,a closed frame on the inside face of the door'closed on its side and topso as to form an inclined plate support opening, a magnetic platecovering said openings. magnet enclosed in said frame and on saidmagnetic plate, the width of said magnetic plate being such that theside edges of said plate are in immediate proximity of the adjacentsidesof the duct to 7 obstruct flow past the side edges of said plate,said plate being held inclined so as to face the flow through'said duct,said plate being extended beyond the top wall of said enclosure so astoform 'a troughbehind'the free edgerof the plate for collecting magneticparticles.

3. In a device for separating magnetic from nonmagnetic materials blownunder pressure to a duct, said duct having an opening an a side thereofbetween an inlet and an outlet of 'saididuct, a door hinged on said sideto cover said opening and being swingable outwardly into open position,a closed frame on the inside face of the door closed on its side and topso as to form an inclined plate support opening, a magnetic platecovering said opening, a magnet enclosed in said frame and on' saidmagnetic plate, the width of said magnetic plate being such that theside edges of said plate are in immediate proximity of the adjacentsides of the duct to obstruct flow past the side edges of said plate,said plate being held inclined so as to face the flow through said duct,said magnetic plate being made in two sections united together by anon-magnetic strip to form arcontinuous plate, and a permanent magnetinside of said enclosure on said plate so as to polarize the respectivesections of said magnetic plate of opposite polarity.

4. In a device for separating magnetic from nonmagnetic materials blownunder pressure to a duct, said duct having an opening on a side thereofbetween an inlet and an outlet of saidduct, a'door hinged on said sideto cover said opening and being swingable outwardly into open position,a closed frame on the inside face of the door closed on its side and topso as to form an inclined 1 proximity ofthe adjacent sides of the ductto'obstruct flow past the. side edges of said'plate, said plate'beingheld inclined so as to face the flow through said duct, said magneticplate being rnade in two sections united together by'a non-magneticstrip to form a continuous plate, and a permanent-magnet inside of saidenclosure on said plate so as to polarize the respective sections ofsaid magnetic plate of opposite polarity, said division being transversewith respect to said plate so that said'difierently polarized sectionsof said plate extend transversely across theportion of said duct. I p a5. In a device for separating, magnetic from 11011: magnetic materialsblown under pressure to a duct, said duct having an opening on a sidethereof between an inlet and an outlet of said duct, a door hinged onsaid side to cover said opening and being swingable outwardly into openposition, a closed frame on theinside face of the door closed on itsside and top so as to'form an inclined plate support opening, a magneticplate covering said opening, a magnet enclosed in said frame and on saidmagnetic plate, the width of said magnetic plate being such that theside edgesof said plate are'in immediate proximity of the adjacent sidesof the duct-to obstruct flow past the side edges of said plate, saidplate being held inclined so as to face the how through said duct, saidmagnetic plate icing made in two sections united together by anon-magnetic strip to form a con tinuous plate, and a permanent magnetinside of said enclosure on said plate so as to polarize the respectivesections of said magnetic plate of opposite polarity, said divisionbeing transverse with respect to said plate so that said differentlypolarized sections of said plate extend transversely across the portionof said duct and a second door and magnetic plate in said duct spacedfrom the first one, the magnetic plate of the second unit beingpolarized in opposite order as regard the transverse sections of theplate as the first unit so as to repel magnetic particles polarized atthe free edge of the first plate.

6. In a magnetic door for an opening on a side of a duct between aninlet and an outlet for the passage of said duct, comprising :a doorfitting over the opening, a support frame projecting firom the doorinwardly of the duct and closed all around so as to form a plate supportinclined with respect to the plane of said door and with respect to thepassage through said duct, the outline of said projection being smallerthan the door opening, a magnetic plate covering said plate support, amagnet inclosed in said support frame and operatively related to saidmagnetic plate, the width of said magnetic plate being such that theside edges of said plate are in the proximity of the adjacent sides ofthe duct to obstruct flow past the side edges of said plate, and a freeedge of said plate projecting beyond the top of said plate support so asto confine a trough behind the free edge of the plate for collectingmagnetic particles swept to and around the free edge of said plate.

7. In a duct having an inlet and an outlet, a magnetic device includinga magnetic plate inclined inwardly with respect to the adjacent side ofthe duct so as to partially obstruct the flow through the duct, means tosupport said magnetic device and said plate in said inclined positionand for moving said device and plate out of said duct, a bathe betweenthe inlet and said magnetic plate extending transversely of the duct andbeing inclined to partially obstruct the flow through said duct, andadjustable support means for said bafiie selectively to position saidbafile so as to direct flow toward said plate or away from the locationof said plate so as to permit removal of said plate without interruptionof flow through the duct.

8. in a duct having an inlet and an outlet and a passage from said inletto said outlet, spaced doors alternately on opposite sides of saidpassage, a magnetic device on each door, a magnetic plate of each devicebeing inclined inwardly of said passage so as to partially obstruct thehow through said passage, each magnetic device and plate being removablefrom said passage by said door; a bafile between the magnetic platenearest to the inlet and said inlet, and another bafiie between themagnetic plates, each bafiie being inclined, projecting into the passageso as to partially obstruct flow, and means to adjust each baifie atwill to direct flow toward the adjacent magnetic plate or to obstructflow to said magnetic plate and thereby permit Withdrawal of such platewith its door from the duct passage during operation of said duct.

References Cited in the file of this patent UNITED STATES PATENTS2,612,268 Merwin Sept. 30, 1952 FOREIGN PATENTS 433,458 Great BritainAug. 9, 1935 643,237 France May 15, 1928

